Devices for altering the propagation of electromagnetic radiation, such as by modulation, represent fundamental building blocks for many technological endeavors. Modulation refers generally to the timewise variation of a property of an electromagnetic wave or signal, such as amplitude, phase, spectral content, direction of propagation, etc., according to a time varying control signal or modulation signal. Optical modulation refers to the modulation of at least one optical signal, where optical signal refers to electromagnetic radiation propagating at one or more optical frequencies, which can include infrared, visible, and ultraviolet frequencies. Electrooptical modulation refers to optical modulation according to an electrical modulation signal.
Practical issues often arise in the implementation of electrooptic modulators in regard to one or more of modulation rate, extinction ratio, spectral range of operation, spectral selectivity, insertion loss, noise performance, device cost, and device size. Other issues arise as would be apparent to one skilled in the art in view of the present disclosure.